A couple weeks ago I pulled the bio-pac (the blue ribbon like material) out of the Bac-Pac II skimmer. Could this be causing my cyno outbreak. I'm thinking it has. I feed frozen food and screen it in RO/DI before feeding. I feed nori once a night and have generally not had cyno problems. I don't remember which started first, the cyno or pulling the bio-pac. I can't think of what else it might have been. Everything is live and well so it's not like something is rotting in there.